Phys.org news tagged with:quantum coherencehttp://phys.org/
en-usPhys.org internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine.Best of Last Week–Magnetic devils staircase, a skinlike display and conscious mind might be less in control than thought(Phys.org)—It was an interesting week in physics as an international team of researchers found that quantum coherence and quantum entanglement are two sides of the same coin—they found a way to show that the two are operationally equivalent. Also, another international team observed a magnetic "devil's staircase"—microscopic analysis of cobalt oxide revealed multiple instances of magnetic structures with degenerate or equal magnetic energies.http://phys.org/news/2015-06-weekmagnetic-devils-staircase-skinlike-conscious.html
Other Mon, 29 Jun 2015 08:30:02 EDTnews354783211Physicists find quantum coherence and quantum entanglement are two sides of the same coin(Phys.org)—Quantum coherence and quantum entanglement are two landmark features of quantum physics, and now physicists have demonstrated that the two phenomena are "operationally equivalent"—that is, equivalent for all practical purposes, though still conceptually distinct. This finding allows physicists to apply decades of research on entanglement to the more fundamental but less-well-researched concept of coherence, offering the possibility of advancing a wide range of quantum technologies.http://phys.org/news/2015-06-physicists-quantum-coherence-entanglement-sides.html
Quantum Physics Thu, 25 Jun 2015 09:20:01 EDTnews354428249The importance of three-way atom interactions in maintaining coherenceQuantum computers will someday perform calculations impossible for conventional digital computers. But for that to happen, the core quantum information must be preserved against contamination from the environment. In other words, decoherence of qubits must be forestalled. Coherence, the ability of a system to retain quantum integrity—-meaning that one part of the system can be used to predict the behavior of other parts—-is an important consideration.http://phys.org/news/2014-12-importance-three-way-atom-interactions-coherence.html
Quantum Physics Mon, 22 Dec 2014 08:20:04 EDTnews338456681Quantum world without queues could lead to better solar cellsIn a recent study from Lund University in Sweden, researchers have used new technology to study extremely fast processes in solar cells. The research results form a concrete step towards more efficient solar cells.http://phys.org/news/2014-12-quantum-world-solar-cells.html
General Physics Fri, 19 Dec 2014 09:00:42 EDTnews338202035Best of Last Week – Superconducting secrets solved, simulating time travel and possible breakthrough in treating autism(Phys.org) —It's been a big week for solving mysteries—first up, a breakthrough has been made in identifying the origin of superconductivity in high temperature superconductors. A team at the University of Cambridge found that moving electrons created twisted "pockets" of electrons in the materials from which superconductivity emerged. Also an Egyptologist unravels an ancient mystery—turns out an ancient army wasn't destroyed by a sand storm after all, it was conquered by another army and then covered up by the losing side. And in Quantum biology: Algae evolved to switch quantum coherence on and off—researchers at UNSW in Australia have uncovered how a type of algae is able to exist in extremely low-light conditions and the discovery adds to the growing list of observations that indicate that quantum phenomena are operating in nature.http://phys.org/news/2014-06-week-superconducting-secrets-simulating-breakthrough.html
Other Mon, 23 Jun 2014 08:30:02 EDTnews322727428Quantum biology: Algae evolved to switch quantum coherence on and offA UNSW Australia-led team of researchers has discovered how algae that survive in very low levels of light are able to switch on and off a weird quantum phenomenon that occurs during photosynthesis.http://phys.org/news/2014-06-quantum-biology-algae-evolved-coherence.html
Biochemistry Mon, 16 Jun 2014 15:00:12 EDTnews322139104Researchers confirm 60-year-old prediction of atomic behaviorResearchers at Washington State University have used a super-cold cloud of atoms that behaves like a single atom to see a phenomenon predicted 60 years ago and witnessed only once since.http://phys.org/news/2014-06-year-old-atomic-behavior.html
Quantum Physics Wed, 04 Jun 2014 05:00:05 EDTnews321028601Quantum-to-classical transition may be explained by fuzziness of measurement references(Phys.org) —The quantum and classical worlds are clearly very different, but how a physical system transitions between them is much less clear. The most well-known attempt to explain the quantum-to-classical transition is decoherence, which is the idea that interactions with the environment destroy quantum coherence, causing a quantum system to become classical.http://phys.org/news/2014-01-quantum-to-classical-transition-fuzziness.html
Quantum Physics Tue, 14 Jan 2014 09:30:01 EDTnews308904012Quantum effects help cells capture light, but the details are obscureSophisticated recent experiments with ultrashort laser pulses support the idea that intuition-defying quantum interactions between molecules help plants, algae, and some bacteria efficiently gather light to fuel their growth. But key details of nature's vital light-harvesting mechanisms remain obscure, and the exact role that quantum physics may play in understanding them is more subtle than was once thought, according to an Overview Article in the January issue of BioScience.http://phys.org/news/2013-12-quantum-effects-cells-capture-obscure.html
General Physics Fri, 06 Dec 2013 12:44:33 EDTnews305556254Diamond 'flaws' pave way for nanoscale MRIBreakthrough offers high-sensitivity nanoscale sensors, and could lead to magnetic imaging of neuron activity and thermometry on a single living cell.http://phys.org/news/2013-11-diamond-flaws-pave-nanoscale-mri.html
Quantum Physics Sun, 24 Nov 2013 13:00:15 EDTnews304515003Searching for quantum physics in all the right placesAn improved method for measuring quantum properties offers new insight into the unique characteristics of quantum systems.http://phys.org/news/2013-07-quantum-physics.html
Quantum Physics Fri, 19 Jul 2013 09:30:01 EDTnews293439383A physicist's best friend: Quantum coherence in diamond augments fluorescence thermometry(Phys.org) —Thermometry – the measurement of temperature – is critical to a wide range of applications, including many industrial processes, biomedical monitoring, and environmental regulatory systems. However, measuring temperature in the presence of high RF (radio frequency) or other electromagnetic fields – such as are found in aerospace, automotive and medical systems – cannot be accomplished using electrical thermometric probes. In these cases, optical sensors that allow scientists to perform thermometry based on thermally-driven changes in ﬂuorescence (brightness) are the instrument of choice. While typical ﬂuorescence thermometers use millimeter-scale optical probes, smaller devices are needed to measure temperatures in intracellular and other nanoscale environments. As a result, the field has witnessed the development of nanoscale ﬂuorescence thermometers based on quantum dots, rare-earth ions and nanogels.http://phys.org/news/2013-06-physicist-friend-quantum-coherence-diamond.html
Quantum Physics Fri, 14 Jun 2013 11:32:30 EDTnews290420303Entanglement in a flash (w/ video)(Phys.org) —JQI researchers under the direction of Chris Monroe have produced quantum entanglement between a single atom's motion and its spin state thousands of times faster than previously reported, demonstrating unprecedented control of atomic motion. This work, which may lead to faster and better quantum computer logic gates, is described a recent issue of Physical Review Letters.http://phys.org/news/2013-06-entanglement-video.html
Quantum Physics Wed, 05 Jun 2013 09:24:38 EDTnews289643064On a clear day: Noise-induced quantum coherence increases photosynthetic yield(Phys.org)—The presence of quantum coherence in photosynthesis in plants, bacteria and marine algae at ambient temperatures is well-established. Two such effects that appeared to be unrelated – enhanced solar cell efficiency and population oscillations in photosynthetic antennae – have been detected in natural and artificial light-harvesting systems. Recently, however, scientists at Texas A&amp;M University and University of California-Irvine have shown that these effects are, in fact, deeply connected: Both arise from the same population–coherence coupling term that is noise-induced and does not require coherent light – meaning that these effects will take place under the incoherent conditions of natural solar excitation. By focusing on the fact that charge separation in light-harvesting complexes occurs in a pair of tightly coupled chlorophylls (the so-called "special pair") at the core of plant, bacteria and algae photosynthetic reaction centers (RCs), and using an analogy between the energy level schemes of the core of the reaction center (including the special pair) and those of the laser/photocell quantum heat engines (QHEs), the scientists were able to demonstrate that both effects operate as QHEs that convert solar photon energy into useful work. The scientists predict that when coexisting they can potentially increase charge separation yield by 27%, and conclude that their findings suggest the viability of artificial solar energy devices based on biomimetic quantum heat engine architectures.http://phys.org/news/2013-02-day-noise-induced-quantum-coherence-photosynthetic.html
Quantum Physics Wed, 27 Feb 2013 11:23:45 EDTnews281186550Noise is not necessarily detrimental to quantum devicesThe researches of the Aalto University and the University of Oulu have succeeded to simulate a phenomenon called motional averaging, which demonstrates that in certain conditions externally-induced fast fluctuations in energy can help stabilize the state of the system. The study shows that noise is not necessarily detrimental to the functioning of quantum devices such as superconducting quantum bits, but under certain circumstances noise can even improve their characteristics.http://phys.org/news/2013-02-noise-necessarily-detrimental-quantum-devices.html
Quantum Physics Mon, 04 Feb 2013 05:45:28 EDTnews279179120Powering lasers through heat In micro electronics heat often causes problems and engineers have to put a lot of technical effort into cooling, for example micro chips, to dissipate heat that is generated during operation. Austrian physicists have now suggested a concept for a laser that could be powered by heat. This idea may open a completely new way for cooling microchips.http://phys.org/news/2012-11-powering-lasers.html
General Physics Tue, 13 Nov 2012 11:16:28 EDTnews272027773Qubits in the quantum sea(Phys.org)—"Quantum weirdness," a phrase related to the power and the un-intuitive nature of quantum reality, is expected to facilitate speeded-up computation—quantum computing—for performing certain specialized tasks, such as factoring numbers. One drawback is that quantum computing depends exquisitely on the parts of a quantum system remaining coherent long enough—even in the face of environmental noise—for the computation to be performed. A proposed scheme should be helpful in sustaining coherence by carefully making mid-calculation corrections.http://phys.org/news/2012-09-qubits-quantum-sea.html
Quantum Physics Mon, 10 Sep 2012 08:32:33 EDTnews266484724Disorderly conduct: Probing the role of disorder in quantum coherenceA new experiment conducted at the Joint Quantum Institute (JQI) examines the relationship between quantum coherence, an important aspect of certain materials kept at low temperature, and the imperfections in those materials. These findings should be useful in forging a better understanding of disorder, and in turn in developing better quantum-based devices, such as superconducting magnets.http://phys.org/news/2012-07-disorderly-probing-role-disorder-quantum.html
Quantum Physics Thu, 19 Jul 2012 15:42:34 EDTnews261931336Physicists build highly efficient 'no-waste' laserA team of University of California, San Diego researchers has built the smallest room-temperature nanolaser to date, as well as an even more startling device: a highly efficient, "thresholdless" laser that funnels all its photons into lasing, without any waste.http://phys.org/news/2012-02-physicists-highly-efficient-no-waste-laser.html
General Physics Wed, 08 Feb 2012 13:00:12 EDTnews247918827A quantum leap in computingWhen American physicist Richard Feynman in 1982 proposed creating a quantum computer that could solve complex problems, the idea was merely a theory scientists believed was far off in the future.http://phys.org/news/2012-01-quantum.html
Computer Sciences Wed, 04 Jan 2012 05:44:44 EDTnews244878248Researchers find more evidence of quantum processes at work in photosynthesis(PhysOrg.com) -- Researchers working together from the University of Chicago and Washington University in St. Louis, have found more evidence that suggests quantum effects are at play as plants use energy from the sun to turn carbon dioxide into organic compounds. As they write in their paper, published in the Proceedings of the National Academy of Sciences, there appears to be a link between coherence and the way energy flows in plants.http://phys.org/news/2011-12-evidence-quantum-photosynthesis.html
General Physics Wed, 07 Dec 2011 09:20:01 EDTnews242468257Playing ping-pong with single electrons: Research provides important technique for transferring quantum informationScientists at Cambridge University have shown an amazing degree of control over the most fundamental aspect of an electronic circuit, how electrons move from one place to another.http://phys.org/news/2011-09-ping-pong-electrons-important-technique-quantum.html
Quantum Physics Wed, 21 Sep 2011 13:00:13 EDTnews235828758Physicists seek to quantify macroscopic quantum states(PhysOrg.com) -- "Scientists have been interested in generating and observing macroscopic quantum superpositions in order to test quantum mechanics at the macroscopic scale," physicist Hyunseok Jeong of Seoul National University in Seoul, South Korea, told PhysOrg.com. "There have been many papers in which the authors claim to have generated mesoscopic or macroscopic superpositions, often called 'Schrodinger cat states.' However, quoting A. J. Leggett in 2002, a question from the theoretical side is &#145;What is the correct measure of "Schrodinger's-cattiness"?' It has been considered difficult to answer this question with a general measure, and the answer has remained to be 'very much a matter of personal taste,' quoting Leggett again. Our work now provides scientists with a theoretical tool to quantify and compare different types of quantum superpositions. This can be a step toward rigorous tests of quantum mechanics in a macroscopic limit."http://phys.org/news/2011-06-physicists-quantify-macroscopic-quantum-states.html
Quantum Physics Wed, 29 Jun 2011 08:20:01 EDTnews228541504Scientists view a quantum jump in real time(PhysOrg.com) -- For more than two decades, scientists have been "watching" electrons in atoms make the jump between energy levels in real time. "Atoms have energy levels, and when electrons 'jump' from one level to another, you can detect this optically. You can encode information in real atoms to make a quantum bit, or qubit," Irfan Siddiqi tells PhysOrg.com.http://phys.org/news/2011-04-scientists-view-quantum-real.html
General Physics Mon, 11 Apr 2011 06:57:35 EDTnews221723788Quantum robins lead the way(PhysOrg.com) -- Did you know that the humble robin uses quantum physics?http://phys.org/news/2011-01-quantum-robins.html
Quantum Physics Fri, 21 Jan 2011 12:49:18 EDTnews214836535'Slow light' on a chip holds promise for optical communicationsA tiny optical device built into a silicon chip has achieved the slowest light propagation on a chip to date, reducing the speed of light by a factor of 1,200 in a study reported in Nature Photonics (published online September 5 and in the November print issue).http://phys.org/news/2010-09-chip-optical.html
Optics & Photonics Sun, 05 Sep 2010 13:26:55 EDTnews202911983Quantum entanglement in photosynthesis and evolutionRecently, academic debate has been swirling around the existence of unusual quantum mechanical effects in the most ubiquitous of phenomena, including photosynthesis, the process by which organisms convert light into chemical energy.http://phys.org/news/2010-07-quantum-entanglement-photosynthesis-evolution.html
Quantum Physics Wed, 21 Jul 2010 15:45:53 EDTnews198945939Combing a qubit: Optical frequency combs could tame quantum bitsPhysicists at the University of Maryland have found a way to turn a precision measurement device into a versatile tool for manipulating quantum bits (qubits). The researchers adapted a device known as an optical frequency comb in their novel approach to performing the sorts of quantum data operations that will be vital for future quantum computers. The research appears in this week's issue of Physical Review Letters and is described in a Viewpoint article by Boris Blinov (University of Washington) in the current edition of APS Physics.http://phys.org/news/2010-04-qubit-optical-frequency-quantum-bits.html
Quantum Physics Mon, 05 Apr 2010 12:34:27 EDTnews189689642Light controls matter, matter controls x-raysLike playing a game of scissors-paper-rock, a team of scientists led by Thornton E. (Ernie) Glover of Lawrence Berkeley National Laboratory's Advanced Light Source (ALS), Linda Young of Argonne National Laboratory, and Ali Belkacem of Berkeley Lab's Chemical Sciences Division has used laser light to control x-ray beams - by first changing the material medium through which the x-rays pass.http://phys.org/news/2010-03-x-rays.html
General Physics Wed, 24 Mar 2010 12:31:18 EDTnews188652654First Pump-Probe Experiment at Linac Coherent Light Source Completed(PhysOrg.com) -- The first experiment using the Linac Coherent Light Source to illuminate molecules via a "pump-probe" technique has been completed by an international team of more than 30 scientists from institutions including Lawrence Berkeley National Laboratory, LCLS and the joint SLAC/Stanford PULSE Institute. Ryan Coffee, physicist with the LCLS Laser Group, presented initial results in a seminar at SLAC on Wednesday, November 18.http://phys.org/news/2009-11-pump-probe-linac-coherent-source.html
General Physics Mon, 30 Nov 2009 17:30:03 EDTnews178822370